WO2016142872A1

WO2016142872A1 - Improved gas bruner

Info

Publication number: WO2016142872A1
Application number: PCT/IB2016/051326
Authority: WO
Inventors: Girolamo Tommaso Emiliani; Luca BRECCIA
Original assignee: Defendi Italy S.R.L.
Priority date: 2015-03-10
Filing date: 2016-03-09
Publication date: 2016-09-15
Also published as: RU2017130719A3; RU2701432C2; EP3268667A1; EP3268667B1; ES2854279T3; RU2017130719A; MX2017011520A; BR112017019156A2

Abstract

A gas burner with at least two flame rings, characterised by consisting of: - an injector holder (6) provided with a single vertical injector (22) positioned centrally on the injector base, - a flame divider (4) with an outer chamber (26) of overall annular development, and an inner chamber (28) of overall circular development, between which an annular cavity (29) is interposed, - a cover (8) made in one piece and comprising a central discoidal portion (54), which upperly closes said inner circular chamber (28), and an annular portion (52) which upperly closes said outer annular chamber (26), and in that: - said flame divider (4) lowerly comprises means (30, 23) for the resting of said flame divider on said injector holder (6, 12), and its connection thereto, - the inner circular chamber (28) of said flame divider (4) comprises a single substantially vertical channel (46) facing said single vertical injector (22) of said injector holder (6), said substantially vertical conduit (46) opening into a radial chamber (47) of venturi effect defined in said inner chamber (28) of the flame divider (4) and upperly bounded by the central discoidal portion (54) of said cover (8), - said flame divider (4) comprises at least one substantially radial channel (36) for fluidic connection between said inner circular chamber (28) and said outer annular chamber (26), said radial chamber (36) being closed upperly by a corresponding radial part (56) of said cover (8), - said at least two flame rings comprising a first ring of flames, generated at ports (42, 43) provided in the outer wall (32) of said outer annular chamber (26) of the flame divider (4), and at least one second ring of flames which can be generated at ports (42, 43) provided in the inner wall (34) of said outer annular chamber (26) of the flame divider (4), or at ports (42, 43) provided in the lateral wall (35) of said inner chamber (28) of the flame divider (4) or at ports (42, 43) provided in both the inner wall (34) of said outer annular chamber (26) and said lateral wall (35) of said inner circular chamber (28).

Description

IMPROVED GAS BURNER

The present invention relates to an improved gas burner.

Single control gas burners with m ultiple concentric flame rings are known, i.e. burners in which the gas feed is controlled by a single tap. These generally comprise an injector holder cup, a flame d ivider resting on the injector holder cup and formed from two parts joined together to define an inner central chamber and an outer annular chamber, a discoidal cover which upperly bounds the central chamber of the flame divider, and an annular cover which upperly bounds the annular chamber of the flame divider.

Hence, known gas burners with multiple concentric rings are formed from a total of five elem ents assem bled together, thei r production cost therefore being fairly high.

One of these known burners is described for example in EP 797048, which comprises five elements: a lower cup-shaped support, an intermediate cylindrical element, a head comprising an inner circular chamber and an outer annular chamber, and two closure covers for said chambers.

To reduce production cost and lessen their assembly complexity, gas burners with m ultiple flame rings have been proposed, formed from four or three elements.

For example, EP 2572141 describes a gas burner with multiple flame rings comprising an injector holder and a flame divider defin ing an outer annular cham ber and an inner circular cham ber, both closed upperly by a single cover. The injector holder comprises two cup-shaped supports and two vertical injectors positioned in a diametrical plane and facing two vertical conduits, which are defined within the flame divider and open upperly into respective arched rad ial cham bers of venturi effect defined in the outer annular chamber. In addition, each arched chamber is fluidically connected to the burner inner chamber via two radial channels.

I n g reater detai l , i n th is bu rner, the gas feed cond u it extends horizontally below the bottom of the two cups along their alignment direction, the two vertical injectors which feed gas to the two arched chambers being applied to it. However, the fact that one injector is closer to the gas inlet than the other means that most of the gas leaves from that injector which is the first to be encountered by the gas. It follows that a greater gas quantity reaches the arched chamber fed by the injector closer to the gas inlet, hence the corresponding flames leaving the ports of said chamber are more consistent than those leaving the ports of the other arched chamber. Essentially, in this burner, the generated flames are neither equal nor are they d istributed uniformly along the entire circumference.

Furthermore, in this known burner the primary air is withdrawn always and exclusively from above the cooking hob.

An object of the invention is to provide a gas burner with only three components, and/or in any event a reduced number of components.

Another object of the invention is to provide a gas burner obtainable at very low production cost.

Another object of the invention is to provide a gas burner which is installable with extreme ease, rapidity and safety.

Another object of the invention is to provide a gas burner in which the flame distribution is uniform along its entire extension. Another object of the invention is to provide a gas burner using either injector holder cups in wh ich the prim ary air is drawn in from below the cooking hob (such as those widespread in certain countries, such as Brazil), or injector holder cups in which the primary air is drawn in from above the cooking hob (such as those widespread mainly in Europe and the Middle East).

These and other objects which wi ll be apparent from the ensuing description are attained according to the invention by a gas burner with the characteristics of claim 1 .

The present invention is further clarified hereinafter by means of some preferred embodiments thereof described by way of non-lim iting example with reference to the accompanying drawings, in which:

Figure 1 is an exploded perspective view of a first installation of the burner according to the invention, seen from above,

Figure 2 is an exploded perspective view thereof seen from below,

Figure 3 is a vertical section therethrough in the assembled configuration, Figure 4 shows a second installation thereof in the same view as Figure 1 , Figure 5 is an exploded perspective view of the instal lation of Figure 4 thereof seen from below,

Figure 6 is a vertical section through the installation of Figure 4 shown in the assembled configuration,

Figure 7 shows the flame divider of the burner of Figures 1 -6 in plan view, Figure 8 is a plan view showing a cover applicable to the flame divider of

Figure 7, Figure 9 is a plan view showing a different embodiment of the flame divider of the burner according to the invention.

Figure 10 is a plan view showing a cover applicable to the flame divider both of Figure 7 and of Figure 9.

As can be seen from the figures, the burner 2 accord ing to the invention comprises a flame divider 4, installable on an injector holder 6, and a cover 8.

In particular, the injector holder 6 is of traditional type and adheres from below to the sheet metal of a cooking hob 10 to which the burner is intended to be fixed by screws. Advantageously, the injector holder 6 can also pertain to a different burner which had been previously mounted on the cooking hob 10, so making its installation particularly easy for the user.

According to a first installation represented in Figures 1 -3, the injector holder 6 comprises a dish 1 2 provided with lateral apertures 1 3 for entry of primary air withdrawn from below the cooking hob. In greater detail, the lateral wall of the dish 12 is provided with a flange 14 projecting outwards, to adhere to the sheet metal of the cooking hob 1 0 from below. Moreover, said lateral wall extends above the flange 1 4 to define a collar 1 5 on which the flame divider 4 rests and is supported.

The injector holder 6 with dish 12 is particularly advantageous as it is small and compact, and moreover, by drawing the primary air from below the cooking hob 1 0, it does not require large dimensions to increase the burner power.

Alternatively, according to a second installation represented in Figures 4 and 6, the injector holder 6 com prises a support shaped as a cup 1 6, completely closed both lowerly and laterally and open at the top, where the lateral wall is provided with a flange 14 jutting outwards to adhere from below to the edge of the aperture provided in the sheet metal of the cooking hob 10, for installing the burner.

The lateral wall of the cup 16 extends upwards beyond the flange 14 to define an emerging rim 1 7, form ing the element on which flame divider 4 rests. In particular, the flame divider 4 is rested on the injector holder 6 such that between these a passage is defined to enable primary air 19 to enter the cup 16 of the injector holder 6 from above the cooking hob 10.

The injector holder with cup 16 is particularly advantageous in that, by withdrawing primary air from above the cooking hob 1 0, it is practical ly insensible to the streaming phenomenon; however, in this case, to increase burner power, the cup dimensions must be increased.

In both the described installations, the injector holder 6 comprises a gas feed conduit 20. It extends horizontally below the bottom of the dish 12 or cup 1 6 of the injector holder 6, it is open at one end 21 for air entry, and communicates with a vertical injector 22 screwed centrally to the base of the injector holder.

Both the aforedescribed installations (i. e. both the first installation represented in Figures 1 -3 and the second installation represented in Figures 4-6) are configured to restingly receive the same flame divider 4.

The flame divider 4 comprises an outer chamber 26 of overall annular shape, and an inner chamber 28 of overall circular shape, between which at least one cavity 29 is defined. A tubular conduit 30 extends downwards from the inner chamber 28 of the flame d ivider 4 and , if used with the injector holder with d ish 1 2 , is inserted into the collar 15 of the cup until the upper edge of said collar 1 5 abuts against the lower surface 27 of the flange surrounding the tubular conduit 30. In greater detail, this contact between the upper edge of the collar 15 and the lower surface of the flange 27 which surrounds the tubular conduit 30 of the flame divider 4 defines a sealed closure which prevents primary air from entering the d ish 1 2 from above the cooki ng hob. I n the case of installation of the flame divider 4 on an injector holder 6 with dish 12, centring is suitably ensured by the insertion of the tubular part 30 of the flame divider 4 into the collar 15 of the injector holder 6.

In addition, downwardly extending shaped projections 23 are provided on the lower surface of the flange 27 of the flame divider 4.

I n contrast, if used with the i nj ector ho lder with cu p 1 6 , these projections 23 engage recessed parts 31 provided on the inner surface of the lateral wall of the cup 16, in such a manner as to define, between the flame divider 4 and the cup of the injector holder 6, apertures to enable primary air 1 9 to enter the cup 16 from above the cooking hob 1 0 (see Figure 6). The connection between said shaped projections 23 and the recessed parts 31 also facilitates centring of the flame divider 4 relative to the injector holder with cup 16.

In both the described instal lations, the manner in which the flame divider 4 rests on the injector holder 6 (both with dish 12, and with cup 16) is such that the flame divider is spaced from the sheet metal 1 0 of the cooking hob to such an extent as to determ ine passages therewith for the secondary air 25 intended for the flames which emerge from the cavity 29 of the flame divider 4.

More particularly, the outer annular chamber 26 of the flame divider 4 presents an outer wall 32 which extends along a cylindrical surface, and an inner wall 34, a certain part of which extends concentrically to the outer wall 32, but then connects to parts substantially radial to the cylindrical wall 35 of the inner chamber 28.

Advantageously, second shaped projections 39 are provided on the lower surface of the outer annular chamber 26 to prevent unbalance, disequilibrium or incorrect positioning of the flame divider 4 in the case of involuntary contacts thereof.

In a first embodiment of the flame divider 4 (see Figures 1 , 4 and 7), the outer annular chamber 26 of the flame divider 4 is connected fluidically to the inner chamber 28 via two substantially radial channels 36 (diametrically aligned) which divide the space between the outer annular chamber 26 and the inner circular chamber 28 into two symmetrical cavities 29. In addition, the outer annular chamber 26 is divided into two arched sectors 39 separated from each other by two diametrically opposite passages 41 forming two inter- ignition channels between the inner cavities 29 of the flame divider 4 and the outside.

In a second embodiment of the flame divider 4 (see Figure 9), the outer annular chamber 26 is connected fluidically to the inner circular chamber 28 via four substantially radial channels 36 (disposed substantially at 90° apart), which divide the space between the outer annular chamber 26 and the inner circular chamber 28 into four equal cavities 29. In addition, the outer annular chamber 26 is divided into four sectors 39 separated from each other by four passages 41 forming four inter-ignition channels.

In an embodiment not shown herein, the outer annular chamber 26 and the i nner circu lar cham ber 28 of the flam e d ivider 4 are fl u id ical ly connected together by a single channel 36. In this case, there is a single cavity 29, which surrounds the inner circular chamber 28, and a single inter- ignition channel 41 .

In greater detail, in both the represented embodiments of the flame divider 4. the outer annular chamber 26 and the inner circular chamber 28 are bounded by a sing le continuous wal l wh ich is provided , along its entire extension with the exception of the parts relative to the radial channel or channels 36, with a plurality of ports for the exit of the primary gas/air mixture and the generation of at least two flame rings. Said ports suitably comprise main ports 42 and secondary ports 43 (see Figures 1 , 2, 4 and 5).

Preferably, said ports 42 and 43 are defined in the outer wall 32 of the outer annular chamber 26, to generate a first ring of outward directed flames, i n the i n ner wa l l 34 of the outer ann u lar cham ber 26 , to generate an intermediate second ring of flames which open into the cavity 29, and in the lateral wall 35 of the inner chamber 28, to generate an internal third ring of flames which also open into the cavity 29.

In further embodiments of the present invention, not shown herein, only two flame rings can be provided, one fed via the ports 42, 43 provided in the outer wall 32 of the outer annular chamber 26, and the other fed via the ports 42, 43 provided in the inner wall 34 of the outer annular chamber or, alternatively, provided in the lateral wall 35 of the inner circular chamber 28 of the flame divider 4.

The tubular conduit 30 of the flame divider 4 defines a vertical channel 46 the bottom of which faces the injector 22 mounted on the injector holder 6 and upperly opens into a radial cham ber 47 of venturi effect, bounded circumferentially by the wall 35 of the inner chamber 28, bounded lowerly by a base 49, and bounded upperly by a cover 8, the position of which, relatively to the flame divider 4, is defined by four centring pegs 50 provided therein.

Preferably, curved bulkheads 37 carrying a central passage aperture are provided between the circumferential wall 35 of the inner chamber 28 and the upper end of the tubular conduit 30, to define arched under-chambers in cooperation with the circumferential wall 35. In particular, the m ixture leaving the tubular conduit 30 enters the arched under-cham bers via the passage aperture defined in the curved bulkheads 37, and emerges from these via the ports 42, 43 provided in the lateral wall 35 of the inner circular chamber 28 of the flame divider 4. In this manner, the mixture leaving the tubular conduit 30 is slowed down to prevent flame detachment and to provided greater stability to the main flame ring fed via the ports 42, 43 provided in the circumferential wall 35 of the inner circular chamber 28.

The cover 8 is made in one piece and comprises an outer annular portion 52, an inner discoidal portion 54 and four shaped radial portions 56 the purpose of which is to connect together the outer portion 52 and the inner portion 54 and to upperly close the channels 36 and/or the passages 41 . In particular, in the cover represented in Figure 8, which is adapted to rest on the flame divider of Figures 1 , 4 and 7, two diametrically aligned radial connection portions 56 are provided for upperly closing the two channels 36 of the flame divider 4. In contrast, in the cover of Figure 1 0 four shaped radial connection portions 56 are provided disposed at 90° to each other, to upperly close the four channels 36; this cover 8 is particularly adapted for resting on the four- channel flame divider of Figure 9, however it can also be suitably used in combination with the two-channel flame divider of Figure 7 (see Figures 1 -6).

If a flame divider 4 with a single radial channel 36 is provided, the cover 8 can com prise a sing le radial portion 56 for connecting the inner discoidal portion 52 to the outer annular portion 56, to upperly close said radial channel 36.

The bu rner accord i ng to the invention operates in the following manner.

The gas entering through the inlet aperture 21 from the conduit 20 emerges from the injector 22 and enters the vertical conduit 46 of the flame divider 4, entraining with it the primary air. This can be drawn from below the cooking hob 1 0, in the case of an injector holder 6 with dish 12 (see Figures 1 -3) or, alternatively, from above the cooking hob 1 0, in the case of a cup injector holder 6, following the path indicated by the arrow 19 of Figure 6.

The stream of gas and primary air wh ich begins to m ix with in the vertical conduit 46 then com pletes its m ixing in the corresponding rad ial venturi chamber 47, bounded upperly by the inner discoidal portion 54 of the cover 8.

The mixture obtained in this manner can thus feed the inner flame ring leaving the ports 42 of the inner circular chamber 28. In addition, the mixture propagates along the channels 36, closed upperly by the connecting portions 56 of the cover 8, to reach the outer annular chamber 26 of the flame divider 4 to feed the outer flame ring and, if provided, also the intermediate flame ring.

The injector holder 6 su itably com prises a support arm 60 for an ignition spark plug 62.

From the aforegoing it is apparent that the burner according to the invention is m uch m ore advantageous than trad itiona l m u lti-flame ring burners, and in particular:

- it is formed from only three pieces and, by virtue of the one-piece die-cast construction of the flame divider without secondary machining operations, is of extremely simple and economical production,

- although intended for a two or three flame ring burner, the cover is also constructed in one piece, this also making the burner production extremely simple and economical,

- it has a radial venturi-type m ixing chamber, contributing to a reduction in the burner overall vertical height,

- it has a single injector positioned at the centre of the injector holder, and this combined with the fact that the radial venturi effect chamber is defined in the inner circular portion of the flame divider, directly facing the injector, means that a single mixture is obtained which is uniformly distributed also with i n the outer an nu lar cham ber of the flam e d ivider, to obtai n the formation of rings of uniform flames along the respective circumferences,

- it enables burners to be constructed in which the same flame divider and the same cover can be applied both on an injector holder with primary air intake from below the cooking hob, and on an injector holder with primary air intake from above the cooking hob, and, finally on already existing injector holders of standard dimensions,

- the assembly of the three components (injector holder, flame divider and cover) is made particularly easy, quick and intuitive.

In particular, the burner according to the invention is different from and more advantageous than traditional burners in that, besides consisting of only three com ponents (the injector holder, the flame divider and the cover), it presents at the sam e t i m e a flam e d istri but ion wh ich i s uniform and homogeneous along its entire circumferential development.

Claims

C L A I M S

1 . A gas burner with at least two flame rings, characterised by consisting of:

- an injector holder (6) provided with a single vertical injector (22) positioned centrally on the injector base,

- a fl am e d iv id er (4) w ith an oute r cham ber (26) of overa l l an n u l ar development, and an inner chamber (28) of overall circular development, between which an annular cavity (29) is interposed,

- a cover (8) made in one piece and comprising a central discoidal portion (54), which upperly closes said inner circular chamber (28), and an annular portion (52) which upperly closes said outer annular chamber (26), and in that:

- said flame divider (4) lowerly comprises means (30, 23) for the resting of said flame divider on said injector holder (6, 12), and its connection thereto,

- the inner circular chamber (28) of said flame divider (4) comprises a single substantially vertical channel (46) facing said single vertical injector (22) of said injector holder (6), said substantially vertical conduit (46) opening into a radial chamber (47) of venturi effect defined in said inner chamber (28) of the flame divider (4) and upperly bounded by the central discoidal portion (54) of said cover (8),

- said flame divider (4) comprises at least one substantially radial channel (36) for fluidic connection between said inner circular chamber (28) and said outer annular chamber (26), said radial chamber (36) being closed upperly by a corresponding radial part (56) of said cover (8), - said at least two flame rings comprising a first ring of flames, generated at ports (42, 43) provided in the outer wall (32) of said outer annular chamber (26) of the flame divider (4), and at least one second ring of flames which can be generated at ports (42, 43) provided in the inner wall (34) of said outer annular chamber (26) of the flame divider (4), or at ports (42, 43) provided in the lateral wall (35) of said inner cham ber (28) of the flame divider (4) or at ports (42, 43) provided in both the inner wall (34) of said outer annular chamber (26) and said lateral wall (35) of said inner circular chamber (28).

2. A burner as claimed in claim 1 , characterised in that said substantially vertical channel (46) facing said single vertical injector (22) is defined within a tubular conduit (30) which extends downwards from the inner chamber (28) of the flame divider (4).

3. A b u rn e r as cl a i m ed i n o n e o r m o re of th e p reced i n g cl a i m s , characterised in that said injector holder (6, 12) is of dish shape and is provided with apertures (13) for the intake of primary air from below the cooking hob (10) in which said burner is to be installed, and in that said resting means (30, 23) comprise said tubular conduit (30), which extends downwards from the i nner cham ber (28) of the flam e d ivider (4) and is sealedly inserted into said dish shaped injector holder (6, 12).

4. A burner as claimed in one or more of the preceding claims, characterised in that said tubular conduit (30) is dimensioned such as to adhere to the inner wall of an upper collar (15) provided in said dish shaped injector holder (6, 12), in such a manner as to hence define a sealed closure which prevents primary air from entering the dish shaped injector holder (6, 12) from above the cooking hob.

5. A burner as claimed in one or more of the preceding claims, characterised in that said injector holder (6, 12) is of cup shape and is closed laterally and at its base, and in that said resting means comprise shaped projections (23) which project downwards from the base of the flame divider (4), to engage in said injector holder (6) in such a manner as to define passages for entry, into the injector holder, of primary air (19) drawn from above the cooking hob (10) in which said burner is intended to be installed.

6. A burner as claimed in one or more of the preceding claims, characterised in that said shaped projections (23) engage in cavities (31) provided in the inner surface of the lateral wall of the cup shaped injector holder (6, 16).

7. A burner as claimed in one or more of the preceding claims, characterised in that said resting means comprise:

- a tubular conduit (30), which extends downwards from the inner chamber (28) of the flame divider (4), and is sealedly inserted into said injector holder (6, 12) in the case in which said injector holder (6, 12) is shaped as a dish provided with apertures (13) for intake of primary air from below the cooking hob (10) in which said burner is intended to be installed,

- shaped projections (23) which project downwards from the base of the flame divider (4), and engage with said injector holder (6, 16) in the case in which said injector holder (6, 16) is shaped as a cup closed both laterally and at its base, in such a manner as to define apertures, for entry into the injector holder, of primary air (19) drawn from above the cooking hob (10) in which said burner is intended to be installed.

8. A burner as claimed in one or more of the preceding claims, characterised in that said flame divider (4) rests on said injector holder (6) by way of said resting means (30, 23) in such a manner as to be spaced from the cooking hob (10) to such an extent as to define, therewith, apertures for the entry, into said annular cavity (29), of secondary air (25) intended for said second flame ring.

9. A burner as claimed in one or more of the preceding claims, characterised in that at least one aperture (41) forming an inter-ignition channel is provided in said outer annular chamber (26).

10. A burner as claimed in one or more of the preceding claims, characterised in that said ports provided in the outer wall (32) of said outer annular chamber (26) of the flame divider (4) and/or in the inner wall (34) of said outer annular chamber (26) of the flame divider (4) and/or in the lateral wall (35) of said inner circular chamber (28) comprise main ports (42) and secondary ports (43).

11. A burner as claimed in one or more of the preceding claims, characterised in that said flame divider (4) comprises two radial chambers (36) of fluidic connection between its inner circular chamber (28) and its outer annular chamber (26).

12. A burner as claimed in one or more of the preceding claims, characterised in that the walls which bound said radial chambers (36) of the flame divider (4) comprise inter-ignition secondary ports for propagating the flames between said ring of flames generated at the ports (42, 43) provided in the inner wall (34) of said outer annular chamber (26) of the flame divider (4) and said ring of flames generated at the ports (42, 43) provided in the lateral wall (35) of said inner circular chamber (28) of the flame divider (4).

13. A burner as claimed in one or more of the preceding claims, characterised in that said injector holder (6) comprises an arm (60) for supporting an ignition spark plug (62) positioned in said annular cavity (29).